package prefix_sum;

import java.util.Scanner;

public class demo1 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int q = in.nextInt();
            int[] nums = new int[n];

            for(int i = 0;i < n;i++) {
                nums[i] = in.nextInt();
            }
            long[] tab = new long[n+1];
            for(int i = 1;i <= n;i++){
                tab[i] = tab[i-1]+nums[i-1];
            }
            for(int i = 0;i < q;i++) {
                int l = in.nextInt();
                int r = in.nextInt();
                System.out.println(tab[r]-tab[l-1]);
            }

        }
    }
}
